Multivariable adaptive fuzzy control for nonlinear building-MR damper systems

Abstract

The development of implementable control strategies that can fully utilize the capabilities of semi-active control devices is a challenging task due to the intrinsically nonlinear characteristics of the problem. In this study, a multivariable adaptive fuzzy controller is derived for a multiple-input and multiple-output nonlinear system, and a multivariable adaptive fuzzy control strategy is proposed accordingly for the use of magnetorheological (MR) dampers to protect buildings against dynamic hazards, such as severe earthquakes and strong winds. The proposed control strategy involves the design of fuzzy controllers and adaptation laws. The control objective is set to minimize the difference between some desirable response and the response of the combined system by adaptively adjusting MR dampers. The use of the adaptation law eliminates the needs for acquiring characteristics of the combined system in advance. The combination of the fuzzy controller and the adaptation law provides a robust control mechanism that can be used to protect nonlinear or uncertain structures subjected to random loads. Numerical and analytical results are presented to illustrate the application of the proposed control strategy.